Firstly I just want to say how interesting this group is, I am
learning loads, most of which I hope I will never need to use ;o)
thanks to all the pro's who are willing to take the time to help
novices like me.
Now ......where were we........................... I would like to
have a programmable thermostat installed instead of my bog standard
room stat. Firstly, as my boiler has a timer attached to it I
presume I will have to get this disconnected?
Does anyone have any recommendations? I would like one that I can
put in different programmes for each day and probably a couple of
temperature changes a day (am I asking too much?)
Also any of you lovely plumbers live anywhere near Eastbourne (or
know of a good CH person around here?) I have a few things I need
to reply remove the x
Best, as in more expensive and unnecessary? If it is single channel anyway,
there is no confusion if it then runs only the hot water. If it is twin
channel, then it can be left entirely as it is anyway as a master switch.
YES, In fact ot needs less wires. It will not need the neutral connection
because as IMM said, they run on battery(s).
Its a simple job, however,
Sods law says that it will be smaller/different shape to your old one so
you'll have to re-decorate the wall afterwards :-)
Then that wall won't match the rest so you'll redo the whole room getting
paint on the carpet....
More nonsense from our resident 'expert'.
The 'timer' will also permit the selection of hot water only etc.
I have a normal fairly basic timer that gives the usual once, twice and
continuous which I use in conjuction with programable thermostat.
However, if going out for the day etc it's much easier to switch the
timer to twice than to mess with the thermostat. The programable stat is
great when the house is occupied all day, but there's no point in
running the heating when it's empty.
*Don't worry; it only seems kinky the first time.*
Dave Plowman firstname.lastname@example.org London SW 12
It is also good for turning off the system totally. I have two programmable
thermostats, one for upstairs and one for downstairs. (There may be a couple
more zones in the future, too). I can turn the entire CH side off by
jiggling the programmer. I could also prevent wayward teenagers setting
their rooms to 30C in the middle of the night too, by using the timer as a
master switch, which will override the programmable thermostat.
One of the most used facilities on my CM67 is the party button -
not for its intended use, but when you're going out for a bit
you can press it and (say) select 3 hours at 15C. At the end of
this period it reverts to the normal program and you come home
to a warm house.
Tony Bryer SDA UK 'Software to build on' http://www.sda.co.uk
Free SEDBUK boiler database browser
There I was about to start a new thread, when I spotted this active
I have a Horstmann Centaurstat7 which I bought from Screwfix. I have
wired my heating so that is always on and the feed to the thermostat
is always live. So the stat has total control of the heating system.
It has 4 periods and rather than weekdays and weekends which many
controllers have it has work days and non workdays. This is a great
feature as my wife works part time therefore need the house to be warm
some of the weekdays. So far so good...
However in practice it is not so good. It is far too sensitive,
meaning that the system frequently gets switched on (ie cold starts)
for 5 minutes or so then switches off. My boiler is fairly old, so
takes a while to heat up its cast iron cylinder, so it scarcely starts
heating the water sometimes, then it switches off! I shudder to think
how innefficient this is and need to do something about it quickly.
I must say I am suprised really - I thought Horstmann was a good make.
Has anyone else:-
- got one of these?
- noticed similar behaviour?
- come up with any solutions?
- come across any optimisations/installers settings like those
mentioned for the Honeywell CM67 previously in this thread?
I'd rather not go to the expense of replacing the controller. If I do
would have to make sure it has the workday/non-workday feature
explained above rather than straight weekday/weekend settings as many
Thanks in anticipation
As frequent readers of uk.d-i-y know this is a control that I use and (I
confess) rather like. I have one in my own home and have fitted one with
just about every heating system I have done substantial work on.
The fact that you have the thermostat clicking off after short while means
either the house was very nearly warm enough already or you have a bad
position for it. Too near to a source of heat or sunlight?
I have also had no complaints from customers about the heating not coming
on or remaining on long enough.
Ed Sirett - Property maintainer and registered gas fitter.
The FAQ for uk.diy is at www.diyfaq.org.uk
Thanks for that Ed. I infer that you have substantial experience in
matters CH, so its reassuring atleast that the Centaurstat has your
seal of approval.
In repsonse to your comments, this is what I have tried so far:
1] the thermostat is in the hall about 4ft from a rad on the
opposite wall. Unfortunately I don't have a TRV on this rad, but I
have turned the valve right down, so its very nearly off. This rad is
logically near the boiler - one of the first on the flow side and last
on the return side, so I was concerned intially that the flow was
choosing the path of least resistance, through this rad and the hall
reaching temp b4 the rest of the house. But this hasn't made any
difference. Very often its obvious the boiler just hasn't got up to
temperature, by feeling the flow pipe out of the boiler just after it
has switched off.
2] removed the 'stat cover from the base and covered the vent holes
with cellotape, to try to make it less responsive - no change here
The external door into the hall is south facing, but is about 15ft
away from the 'stat, so I don't see direct/indirect heat from the sun
being a problem.
The only other thing occuring to me as I write is that the 'stat is
located on single-skin wooden panelling alongside the staircase. On
the other side of this are steps down to the basement. There could be
2 issues here: temperature fluctuations conducting through the wood -
perhaps unlikely as wood by nature is relatively insulating. The more
likley cause is small draughts coming into the back of the 'stat. The
wire to the stat disappears through a hole the panneling down into the
basement, where the boiler is. At the moment the basement is
otherwise unheated and there is permanent fresh-air ventilation. As I
write I am unsure whether that hole is totally air-tight... Could
have hit the jackpot - will check it out when I get home tonight...
The only other thing I had thought of doing - a nasty low-tech effort
- would be putting a bit of fibre-glass lagging inside the 'stat,
again to try and make it less responsive.
Anyway - I'll check that hole tonight and post back if I've cracked it
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